React js Deep Linking
I fixed my problem. The answer was:
I have load the Project via Netlify. Then create a new file "_redirects". This was placed in the folder "public" (where also the index.html is inside). in this fil is "/* /index.html 200 ".
I also had to add the following after my build command:
("react-scripts build") "&& echo '/* /index.html 200' | cat >build/_redirects"
so that it looks like this in the final result:
"build": "react-scripts build && echo '/* /index.html 200' | cat >build/_redirects ",
I hope that I could help the anyone with the same problem.